BIOLOGY Questions For SSC CHSL 2017-18

Q1. Development of an egg without fertilization is called(a) Gametogenesis(b) Parthenogenesis(c) Oogenesis(d) Metamorphosis

Q2. In the process of dialysis, used on patients with affected kidneys, the phenomenon involved is(a) Diffusion(b) Absorption(c) Osmosis(d) Electrophoresis

Q3. Bleeding of gums and loosening of teeth is caused due to deficiency of (a) Vitamin A(b) Vitamin B(c) Vitamin C(d) Vitamin D

Q4. Which one of the following is true regarding plant cells and animals cells?(a) Plant cells contain chloroplast while animal cells do not.(b) Plant cells are small while animal cells are large in size(c) Plant cells contain nucleus while animal cells do not(d) Plant cells and animal cells are similar in all respects

Q14.The radio-isotope used to detect blood clots in the circulatory system is -(a) Arsenic-74(b) Cobalt-60(c) Iodine-131(d) Sodium-24

Q15. Microscopic organism which passively float on the surface of water is called__________(a) Zooplanktons(b) Phytoplankton(c) Both (A) & (B)(d) None of the above

Solutions:

S1. Ans.(b)

Sol. Parthenogenesis is a form of a sexual reproduction in which growth and development of embryos occur without fertilization. In plants, parthenogenesis means development of an embryo from an unfertilized egg cell, and is a component process of apomixes.

S2. Ans.(c)

Sol. Dialysis is the artificial process of getting rid of waste (diffusion) and unwanted water (ultra filtration) from the blood. This process is naturally done by our kidneys. It is the artificial replacement for lost kidney function (renal replacement therapy). The elimination of unwanted water (ultra filtration) occurs through osmosis – as the dialysis solution has a high concentration of glucose, it results in osmotic pressure which causes the fluid to move from the blood into the dialysate.

S3. Ans.(c)

Sol. Scurvy is a disease caused by the deficiency of vitamin C or ascorbic acid. The symptoms are bleeding gums, loosening of teeth, swollen and painful joints, bleeding in tissues and general fatigue (tiredness). Vitamin C is destroyed on heating.

S4. Ans.(a)

Sol. Plant cells have several structures not found in other eukaryotes. In particular, organelles called chloroplasts allow plants to capture the energy of the Sum in energy-rich molecules; cell walls allow plants to have rigid structures as varied as wood trunks and supple leaves; and vacuoles allow plant cells to change size.

S5.Ans.(b)

Sol. Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland (hypophysis). The hypothalamus is responsible for certain metabolic processes and other activities of the autonomic nervous system. It synthesizes and secretes certain neurohormones, often called hypothalamic-releasing hormones, and these in turn stimulate or inhibit the secretion of pituitary hormones. The hypothalamus controls body temperature, hunger, thirst, fatigue, sleep, and circadian cycles.

S6. Ans.(d)

Sol. Open circulatory system is the one in which blood does not circulate only inside blood vessels but it also falls in cavities of tissues. The internal organs are suspended in a network of blood-filled sinuses or open spaces which collectively form the haemocoel.

S7. Ans.(c)

Sol. Chromosomes are the structures that hold our genes. Genes are the individual instructions that tell our bodies how to develop and functions; they governour physical and medical characteristics, such as hair color, blood type and susceptibility to disease. The typical number of chromosomes in a human cell is 46 – two pairs of 23 – holding an estimated 25,000 genes.

S8. Ans.(b)

Sol. The Olive Ridley is considered the most abundant sea turtle in the world, with an estimated 800,000 nesting females annually. The Olive Ridley gets its name from the olive coloration of its heart-shaped top shell (carapace).

S9. Ans.(a)

Sol. Gastric glands within the stomach produce secretions called gastric juice. Hydrochloric acid (HCI) converts pepsinogen to pepsin which breaks down proteins to peptides. HCI maintains a pH in the stomach of approximately 2.0. It also dissolves food and kills microorganisms.

S10. Ans.(c)

Sol.Haemophilia is a group of hereditary genetic disorders that impair the body’s ability to control blood clotting or coagulation, which is used to stop bleeding when a blood vessel is broken.

S11. Ans.(d)

Sol. Litmus is a water-soluble mixture of different dyes extracted from lichens.Litmus is used as PH indicator, being red under acidic condition and blue under alkaline condition.

S12. Ans.(a)

Sol. Water available in soil for the root of Plant is Capillary Water.

S13. Ans.(b)

Sol. The orientation of a plant or other organism in response to light is either towards the source of light or away from it. This is known as phototropism.

S14. Ans.(d)

Sol.Radioactive isotopes are effectively used as tracers for diagnostic purposes in medicine. Arsenic-74 isused to detect tumours. Sodium-24 is used to detect blood clots in the circulatory system. Iodine-131 (I-131) is used to determine the activity of the thyroid gland. Cobalt-60 is used in the treatment of cancer.

S15. Ans.(c)

Sol. Planktons are microscopic organisms which are floating passively on suface of open water ecosystems. These are present in both fresh water and marine habitats, drifting with current. Planktons are diverse in nature, broadly divided in zooplankton and phytoplankton .